The NAACP approved a resolution last week calling on tea party activists and others to "repudiate the racist element and activities" within the political movement.

Tea party organizers say racism does not have any place in their activities.

Critics have pointed to signs and other actions at tea party gatherings as evidence of racist elements.

In defending the National Tea Party Federation, spokesman David Webb said Sunday that the coalition of local and regional tea party groups has expelled the Tea Party Express from its ranks for refusing to remove its spokesman, Mark Williams.

The conservative radio host had posted a blog entry that satirized the NAACP and referred to its president, Benjamin Jealous, as "Tom's nephew and NAACP head colored person."

The blog post was "clearly offensive," Webb said.

"Self-policing is the right and the responsibility of any movement or organization," Webb said on "Face the Nation" on CBS. "I denounce any acts that I see many leaders do."